中文摘要：

万宝沟群位于柴达木地块南缘、东昆仑造山带中段，主要由溢流相玄武岩、火山和陆源碎屑岩以及灰岩组成。万宝沟玄武岩可以分为两类：高Ti碱性玄武岩和低Ti拉斑玄武岩，前者具有高的Ti/Y（502～660）、Nb/Y（0.8～1.6）值和TiO2含量（2.76%～4.97%），与OIB类似；后者具有相对低的Ti/Y（383～439）、Nb/Y（0.3～0.4）值和TiO2含量（1.80%～2.49%），与E-MORB类似。SIMS锆石年代学结果表明万宝沟玄武岩形成于新元古代（762±2 Ma）。野外地层和地球化学特征显示万宝沟玄武岩可能形成于大陆裂谷或者初始洋盆环境，代表Rodinia超大陆裂解的峰期阶段。

英文摘要：

The Wanbaogou Group is located on the southern margin of the Qaidam block and along the middle segment of the East Kunlun orogenic belt. It consists of effusive basaltic lavas, terrigenous and volcaniclastic rocks, and limestones. The Wanbaogou basalts can be divided into two groups：high-Ti （HT） alkaline and low-Ti （LT） tholeiitic basalts. The former shows high Ti/Y ratios （502~660）, Nb/Y ratios （0.8~1.6） and TiO2 values （2.76%~4.97%）, similar to features of OIB. The latter has relatively low Ti/Y ratios （383~439）, Nb/Y ratios （0.3~0.4） and TiO2 values （1.80%~2.49%）, which resembles E-MORB. Zircon SIMS analyses indicate that the Wanbaogou basalts were formed in the Neoproterozoic （762±2 Ma）. The field occurrence and geochemical characteristics suggest that the Wanbaogou basalts were formed in a continental rift or an initial oceanic basin environment, and represented the peak stage of the Rodinia breakup.